Conventionally, for antenna devices provided to weather radars and the like, a configuration has been known, which can vertically rotate to change an elevation angle of the antenna and can horizontally rotate to change an azimuth of the antenna to orient an open face of the antenna and the like toward an observation target. Moreover, a configuration for, for example, a case of performing satellite communication has been known, which can vertically rotate and horizontally rotate to orient the open face of the antenna and the like toward a direction of the satellite.
Patent Document 1 discloses an antenna device (antenna orienting device) which can vertically and horizontally rotate. This antenna device has a base configured to support the antenna and the like. Further, an azimuth servomotor that is a power source for the horizontal rotation is disposed on the base. Moreover, an elevation servomotor that is a power source for the vertical rotation is disposed to a back side of the antenna (opposite side to a radiation face).
Patent Document 2 discloses an antenna device (antenna power feeding device) using a radio wave comprised of a vertical polarized wave and a horizontal polarized wave. In this antenna device, a part configured to generate the radio wave is connected with a part (antenna) configured to radiate the ratio wave, via a rotary joint (rotational coupler).
Patent Document 3 discloses an antenna device using a radio wave comprised of a vertical polarized wave and a horizontal polarized wave. This antenna device includes two rotary joints in the vicinity of an edge part (a part away from the center) of the antenna. Further, a waveguide for the vertical polarized wave and a waveguide for the horizontal polarized wave are respectively disposed to reach a central part of the antenna via these rotary joints.
With these configurations, a rotational shaft for the vertical rotation of the antenna passes through the inside of the antenna, and therefore, an operation area of the antenna when vertically rotating can be suppressed.